Orcas in the Antarctic
An iconic predator, as beautiful as it is deadly
What you need to know about the Orca Whale
Our Expert Says… "Although a siting can never be guaranteed, there's always a good chance of seeing these amazing creatures on your cruise. Their high dorsal fin gives your guides and crew a head start in spotting them even at a distance. They are so iconic, if you're having a fantastic encounter, the guides and captain might decide to cancel a planned landing or excursion just so that you can enjoy being among these beautiful and intelligent marine predators."
The orca or killer whale is one of the world’s most iconic predators. Its stunning black and white coloring, 1.8m (6ft) dorsal fin, and efficiency as a hunter put it high on the list of “must-see” animals for polar travelers.
Although officially one species there are currently debates among scientists about reclassifying orcas into distinct subspecies or even separate species. Although found in every ocean in the world, orcas do show distinctive variations in size and shape among various populations distinct enough to warrant debate about their classification.
Apart from the most northerly Arctic waters, orcas can be found in both northern and southern polar waters. Some of the highest densities of orcas can be found off the coasts of Norway and in the sub-Antarctic southern oceans. Their huge range and widespread distribution make it difficult to ascertain how plentiful they are, but there is a consensus that there are at least 50,000 individuals worldwide.
Although known as toothed whales, orcas are actually the largest member of the dolphin family. Males grow to around 7.5m (25ft) long and weigh in at 6 tons, with females being shorter and lighter. Like other members of the dolphin family, orcas have excellent echolocation senses using the reflected returns of clicking sounds they make to find prey and avoid obstacles.
Killer whales have no known predators and they hunt in packs. Antarctic orcas can be seen “wave hunting”, where they swim in groups together to cause a large bow wave that washes over ice floes, dislodging seals or penguins resting there into the water and into the path of other waiting orcas.
Orcas have a varied diet, with some differences depending on which part of the world they live in, but it includes fish, squid, turtles, seabirds, and marine mammals, including other dolphin and whale species. On average a killer whale will consume 230kg (500lb) of food on a typical day.
It’s well known that orcas have a highly complex social structure based around close family bonds. Loose groups of orcas, known as pods, gather together based around shared family lines. Larger groups, known as clans, may also gather. These will all share some family connections, and also show similar “acoustic signatures” in their calls. Killers whales are one of the few animals who experience menopause and then live on long after they lose fertility. Females can usually fall pregnant until they are around 40 years old, and then go on to live to about 70 or 80.
Orcas have the second-heaviest brain of all marine mammals and have been observed problem solving and actively teaching their calves hunting skills rather than relying on them to simply copy. An Alaskan population have learned how to steal fish from longlines and have overcome tactic and methods used by fishermen to try and prevent them from stealing catches.
Despite their fierce reputation, there have been no confirmed fatalities to humans caused by wild killer whales, and very few reported deliberate attacks.